I have my second BMPC4K that seems to have the same problem as the first one, it will not shut off unless plugged into AC power. On battery only the camera shuts off, then starts up again in about 1 second. This is a brand new camera, and the second BMPC4K with the same problem I've had. BM emailed and tried to help me on the first camera but nothing worked including firmware upgrade.
Anybody have a solution or similar problem?